[GRAPHICS]An efficient macrolactonization protocol devoid of any base was developed derived from the use of vinyl esters in transesterification. Subjecting a hydroxy acid and ethoxyacetylene to 2 mol % [RuCl2(p-cymene)](2) in toluene followed by addition of camphorsulfonic acid or inverse addition provided macrolactones in good yields.
Ruthenium-Catalyzed Alkene-Alkyne Coupling: Synthesis of the Proposed Structure of Amphidinolide A
作者:Barry M. Trost、John D. Chisholm、Stephen T. Wrobleski、Michael Jung
DOI:10.1021/ja027883+
日期:2002.10.1
C-25. The C-7 to C-15 subunit involves introduction of chirality by an asymmetric dihydroxylation. The route to the C-16 to C-25 subunit introduces chirality by a Pd-catalyzed asymmetricallylicalkylation and an asymmetric epoxidation. Assembly of the three subunits employs the Ru-catalyzed addition inter- and intramolecularly. The synthesis culminated in the formation of the assigned structure and
Optical recording media with triplet-sensitized isomerization
申请人:Eastman Kodak Company
公开号:US07459263B2
公开(公告)日:2008-12-02
The invention relates to an optical recording material comprising: a polymeric matrix; a dewarbenzene derivative reactant capable of undergoing isomerization to a benzene product upon triplet excitation, thereby causing a change in optical properties; and a sensitizer capable of absorbing actinic radiation to cause triplet energy transfer to said reactant, wherein the algebraic sum of the excitation energy of said sensitizer and its reduction potential is at least 0.05 eV less than the oxidation potential of said reactant, thereby precluding one-electron oxidation of said reactant. The invention further relates to an optical device comprising regional variations in concentrations of reactants and products produced by triplet chain isomerization, thereby providing a pattern of intelligence.
[GRAPHICS]An efficient macrolactonization protocol devoid of any base was developed derived from the use of vinyl esters in transesterification. Subjecting a hydroxy acid and ethoxyacetylene to 2 mol % [RuCl2(p-cymene)](2) in toluene followed by addition of camphorsulfonic acid or inverse addition provided macrolactones in good yields.
Total Synthesis of (+)-Amphidinolide A. Assembly of the Fragments
作者:Barry M. Trost、Stephen T. Wrobleski、John D. Chisholm、Paul E. Harrington、Michael Jung
DOI:10.1021/ja0533646
日期:2005.10.1
The structure elucidation of (+)-amphidinolide A, a cytotoxic macrolide, has been accomplished by employing a combination of totalsynthesis and NMR spectroscopic analysis. Amphidinolide A possesses two skipped 1,4-diene subunits which are accessible by ruthenium-catalyzed alkene-alkyne couplings. Previous total syntheses had revealed that the reported structure was incorrect; therefore, to incorporate
Optical recording media with triplet-sensitzed isomerization
申请人:Farid Y. Samir
公开号:US20050136357A1
公开(公告)日:2005-06-23
The invention relates to an optical recording material comprising: a polymeric matrix; a dewarbenzene derivative reactant capable of undergoing isomerization to a benzene product upon triplet excitation, thereby causing a change in optical properties; and a sensitizer capable of absorbing actinic radiation to cause triplet energy transfer to said reactant, wherein the algebraic sum of the excitation energy of said sensitizer and its reduction potential is at least 0.05 eV less than the oxidation potential of said reactant, thereby precluding one-electron oxidation of said reactant. The invention further relates to an optical device comprising regional variations in concentrations of reactants and products produced by triplet chain isomerization, thereby providing a pattern of intelligence.